It comes a month after Lufthansa cancelled nearly 700 out of a total 1,800 flights due to half a day of warning strikes.

Lufthansa board member Stefan Lauer said the action, described as a 24-hour warning strike, was "de facto an all-out strike" that was "a completely excessive measure that can in no way be justified in view of the current state of negotiations".

Verdi has accused management of "playing with employees' fears about their future and their jobs" in refusing to make any concrete guarantees.

The union has complained that the offer proposed by management represented an increase of less than one percent over a period of one year.